using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Windows.Forms; using System.Security.Cryptography; namespace WindowsFormsApp1 { PUBLIC partial class Form1 : Form { PUBLIC string publicKeyString; PUBLIC string privateKeyString; PUBLIC string encryptedText; PUBLIC string decryptedText; PUBLIC Form1() { InitializeComponent(); } PRIVATE void btnPublic_key_Click(object sender, EventArgs e) { var cryptoServiceProvider = NEW RSACryptoServiceProvider(2048); //2048 - Długość klucza var publicKey = cryptoServiceProvider.ExportParameters(FALSE); //Generowanie klucza publiczny publicKeyString = GetKeyString(publicKey); lblPublic_Key.Text = publicKeyString; } PRIVATE void btnPrivate_key_Click(object sender, EventArgs e) { var cryptoServiceProvider = NEW RSACryptoServiceProvider(2048); //2048 - Długość klucza var privateKey = cryptoServiceProvider.ExportParameters(TRUE); //Generowanie klucza prywatnego privateKeyString = GetKeyString(privateKey); lblPrivate_Key.Text = privateKeyString; } PUBLIC static string GetKeyString(RSAParameters publicKey) { var stringWriter = NEW System.IO.StringWriter(); var xmlSerializer = NEW System.Xml.Serialization.XmlSerializer(typeof(RSAParameters)); xmlSerializer.Serialize(stringWriter, publicKey); RETURN stringWriter.ToString(); } PRIVATE void btnEncryptiontext_Click(object sender, EventArgs e) { string tekst = textBox_text.Text; encryptedText = Encrypt(tekst, publicKeyString); //Szyfrowanie za pomocą klucza publicznego tb_Encryptiontxt.Text = encryptedText; IF (publicKeyString == NULL) { MessageBox.Show("Najpierw wygeneruj kklucz", "Error"); } } PUBLIC static string Encrypt(string tekst, string publicKeyString) { var bytesToEncrypt = Encoding.UTF8.GetBytes(tekst); using (var rsa = NEW RSACryptoServiceProvider(2048)) { try { IF (publicKeyString == NULL) { MessageBox.Show("Najpierw wygeneruj kklucz", "Error"); } ELSE { rsa.FromXmlString(publicKeyString.ToString()); } var encryptedData = rsa.Encrypt(bytesToEncrypt, TRUE); var base64Encrypted = CONVERT.ToBase64String(encryptedData); RETURN base64Encrypted; } finally { rsa.PersistKeyInCsp = FALSE; } } } PRIVATE void btn_Decrypttxt_Click(object sender, EventArgs e) { encryptedText = tb_Encryptiontxt.Text; decryptedText = Decrypt(encryptedText, privateKeyString); tb_Decryptiontxt.Text = decryptedText; } PUBLIC static string Decrypt(string encryptedText, string privateKeyString) { var bytesToDescrypt = Encoding.UTF8.GetBytes(encryptedText); using (var rsa = NEW RSACryptoServiceProvider(2048)) { try { // server decrypting data WITH PRIVATE key rsa.FromXmlString(privateKeyString); var resultBytes = CONVERT.FromBase64String(encryptedText); var decryptedBytes = rsa.Decrypt(resultBytes, TRUE); var decryptedData = Encoding.UTF8.GetString(decryptedBytes); RETURN decryptedData.ToString(); } finally { rsa.PersistKeyInCsp = FALSE; } } } PRIVATE void textBox1_TextChanged(object sender, EventArgs e) { } } }